java - JFreeChart y 轴图例随着小数字消失

Question

我正在尝试显示条形图来显示一些结果，但因为我的结果是非常小的数字，例如 10*10^-10，所以 y 轴的比例会随着这些值而消失。如何用小数字显示比例尺？

这是我的代码:

    private JPanel createBarChartBER(double ber, double[] calculatedQFactor) 
    {
    double [] berValues = new double[calculatedQFactor.length];
    berValues[0]=berCalculation(calculatedQFactor[0]);
    berValues[1]=berCalculation(calculatedQFactor[1]);

     final DefaultCategoryDataset dataset = new DefaultCategoryDataset();

        dataset.addValue(getBer(), "ITU Standards", "ITU Standards");
        dataset.addValue(getBer(), "Closest ONU", "Closest ONU");
        dataset.addValue(getBer(), "Further ONU", "Further ONU");

        // create the chart...
        final JFreeChart chart = ChartFactory.createBarChart(
            "BER Values",         // chart title
            "",               // domain axis label
            "Value",                  // range axis label
            dataset,                  // data
            PlotOrientation.VERTICAL, // orientation
            true,                     // include legend
            true,                     // tooltips?
            false                     // URLs?
        );
        // NOW DO SOME OPTIONAL CUSTOMISATION OF THE CHART...


        // set the background color for the chart...
        chart.setBackgroundPaint(Color.BLACK);
        // get a reference to the plot for further customisation...
        final CategoryPlot plot = chart.getCategoryPlot();
        plot.setBackgroundPaint(Color.lightGray);
        plot.setDomainGridlinePaint(Color.white);
        plot.setRangeGridlinePaint(Color.white);

        // set the range axis to display integers only...
        NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
        rangeAxis.setRange(0.0, Math.pow(10, -9));
        rangeAxis.setTickUnit(new NumberTickUnit(Math.pow(10, -3)));
        rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
        rangeAxis.setAutoRangeIncludesZero(true);
        NumberAxis yAxis = (NumberAxis) plot.getRangeAxis();
        yAxis.setAutoRangeMinimumSize(Math.pow(10, -3));
        yAxis.setTickLabelPaint(Color.WHITE);
        rangeAxis.setTickLabelPaint(Color.WHITE);
        // disable bar outlines...
        final BarRenderer renderer = (BarRenderer) plot.getRenderer();
        renderer.setDrawBarOutline(false);

        // set up gradient paints for series...
        final GradientPaint gp0 = new GradientPaint(
            0.0f, 0.0f, Color.blue, 
            0.0f, 0.0f, Color.white
        );
        final GradientPaint gp1 = new GradientPaint(
            0.0f, 0.0f, Color.green, 
            0.0f, 0.0f, Color.white
        );
        final GradientPaint gp2 = new GradientPaint(
            0.0f, 0.0f, Color.red, 
            0.0f, 0.0f, Color.white
        );
        renderer.setSeriesPaint(0, gp0);
        renderer.setSeriesPaint(1, gp1);
        renderer.setSeriesPaint(2, gp2);
        renderer.setMaximumBarWidth(.1);
        final CategoryAxis domainAxis = plot.getDomainAxis();
        domainAxis.setCategoryLabelPositions(
            CategoryLabelPositions.createUpRotationLabelPositions(Math.PI / 6.0)
        );
        domainAxis.setTickLabelPaint(Color.WHITE);
        final ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new Dimension(400, 300));
        chartPanel.setForeground(Color.WHITE);

        JPanel jPanel1 = new JPanel();
        jPanel1.setLayout(new java.awt.BorderLayout());
        jPanel1.add(chartPanel ,BorderLayout.CENTER);
        jPanel1.validate();

        return jPanel1;
       }

Answer 1

尝试:

axis.setAutoRange(true);
axis.setAutoRangeIncludesZero(false);